Heater switch and circuit



P s. A. GRISWOLD 2,015,624

VHEATER SWITCH AND CIRCUIT Filed Oct. 8, 1952 Z Sheets-Sheet l T E ENVENTOR $AMUEL. A. GRBSWGLD BY HIS ATTORNEYS W W MM m W Sept. 24,

S. A. GRISWOLD HEATER SWITCH AND CIRCUIT Filed Oct. 8; 1952 2 Sheets-Sheet 2 i illlllllllylil.

INVENTOR SAMUEL A. GRISWOLD BY IHIS ATTORNEYS Patented Sept. 24, 1935 OFFICE HEATER SWHTCH AND @IllltiCiUE'll nectiicut Application @ctober 8,

10 (Claims.

switches each of which controls connections to an electric translating device such as a heater unit, this circuit being characterized by the fact l that each device or heater unit is isolated from the power lines when its switch is in circuit breaking position.

Another object of my invention is to provide-a circuit including a plurality of interconnected 2o switches each of which controls an electric translating device such as a heater unit, this circuit being characterized by the provision of connections for the prevention of excess current drain from the power lines.

25 Another object of my invention is to provide a circuit including a plurality of interconnected switches each of which controls connections to an electric translating device such as a heater unit in which circuit the completion of connections on" 30 one switch to its heater unit is permitted when the other switch is in any position but the position in which it establishes the connections for giving maximum heat in the heater unit which it controls, and vice versa.

35 Another object of my invention is to provide a circuit of the above type in which the above objects are accomplished by the use of two deck switches.

Other objects and advantages or" my invention 40 will become apparent as it is described in connectlon with the accompanying drawings.

In the drawings Figures 1 to 9 show circuit diagrams of a pair of switches each of which primarily controls con- 45 nections to a two element heating unit and is interconnected according to the principles of my invention. These figures show the switches in different positions for establishing circuit connections to give difierent combinations of heating 59 effects.

Figure 10 is an elevation view partly in section of the type of switch used in my new circuit.

Figure 11 is a plan view of a pair of switches like the switch shown in Figure 10 but with the 55 covers of the switches removed and with dia- 1032, Serial No. 636,031 a grammatic circuit connections made according to my invention.

Referring to the drawings the switches used in carrying out my invention are identical and each comprises a circular porcelain base 800 with a re= 5 cess or well it)?! in the center for the reception of conventional rotary snap switch mechanism of any suitable type such as that shown in the Harrington Patent 1,466,507 patented August 28, 1923. The switch mechanism is controlled manually by M a handle Hi l which may be of the type shown in the Carlson Patent 1,690,052 patented October 30, 1928. The arrangement of the stationary con== tacts about the switch base and of the movable switch contacts upon the switch spindle may be is varied within the scope of my invention and need not be exactly as illustrated and hereinafter de-= scribed. I prefer to use a combination of long and short stationary switch contacts which are engaged and disengaged by long and short mov= as able switch blades as the switch is actuated. Preferably l locate the contacts in two planes with one of the contacts offset so that its contact ing surface is above the upper plane so as to be engaged only by a movable switch blade especially provided for this purpose and which is offset from the other blades into the same plane as the contacting surface of the offset stationary contact.

Referring to the switch 320 which I provide primarily for controlling connections to the heating unit composed of the resistance elements A and B, the lower contacting plane includes one long contact 30a and three short contacts 30b, 30c, and 3002, each or which may be provided with conventional binding means for the wire connections or"- the circuit. The contacts 305, 20c and 30d are 90, 180 and 2l0, respectively in. advance of long contact 000;. The upper contacting plane includes a long contact 30c, a short contact 30 a short contact 30g offset upwardly from the upper plane, and a long contact 30%, the contacts 30f, 30g and 30h, being 90, 180 and 270 in advance of long contact 00c, respectively. The lower contacting plane has a movable switch member comprising three switch blades a, 00b, 500, the blades 06a, and 5% being long and the blade 500 being short. The blade 5% is 90 in advance of 50a and the blade 000 is 180 in advance of 50a. The upper contacting plane contains a movable switch member 50 having four switch blades 6011,6027, c, and Md. The blades 60b and 600 are in advance of 60a and like 00a are long contacts, but the end portion of blade $00 is offset to lie above the end portion oi 60b in the same plane as the con- 55 tacting surface of the offset stationary contact 100 so as to contact therewith as the switch is rotated. Switch blade 60d is a short blade and is 180 in advance of 80c.

The upper and lower movable contact members are fixedly mounted upon the switch spindle, with their blades in predetermined relation, and they rotate together in a manner well known to those skilled in the art.

In the switch as shown in Figures 10 and 11 the offset contact 309 is directly above the short lower contact BM in the lower plane, and the long contact the in the upper plane is directly above the short lower contact 30b in the lower plane, but this relationship of the contacts in the,

upp r and lower plane need not necessarily be maintained as is illustrated by the circuit diagrams of Figures 1 to 9 wherein, for the purpose of simplifying the connections of the diagram the contact 30a is shown as if directly above the contact 3011. It therefore will be obvious to those skilled in the art that the relationship of the contacts in the upper and lower planes may be varied to suit the desires of a particular manufacturer, and such variations are within the scope of this invention.

The switch 40 may be constructed exactly like the switch 30 having the same long and short contacts in each of the lower and upper planes and an offset contact lug like the offset contact 309. The short contacts "lb, 40c, 40d in the lower plane will be 90, 180 and 270 in advance, respectively, of the long lower contact 40a, and the upper contacts 40], "g and "It will be 90 180 and 270 in advance, respectively, of the long upper contact We.

For convenience in describing this invention the four positions of the switches will be designated as high, medium, low and of! positions, the

a high position being the position wherein a switch may complete connections for giving a maximum 'degree of heat from a heating unit, the medium position being the position of the switch in which the connections are completed for giving a lesser degree of heat than the maximum, but more than the least amount of heat, and the low position being the position in which connections are completed for giving the least amount of heat from the heating units, and the oil position being the position in which the circuit from the power lines through the heating units is broken. As will hereinafter appear, in high heat position both elements of the resistance unit are connected in multiple across the power lines. In

medium heat position only one element is con-- nected across the lines. In low position both elements are connected in series across the power lines.

Referring now to the circuit connections, the switch 10. as heretofore stated, is provided primarily for controlling the connections to a heating unit comprising two resistance elements A and B, while the switch 40 is provided primarily for controlling the connections to a heating element comprising two resistance units M and N.

But the switches 30 and 40 are interconnected as will hereinafter bemore fully described so that when both switches are in high heat position, no circuit through any element of the heating units is completed so that no current flows through either heating unit, nor can the circuit be completed for high heat to either unit so long as the switch controlling the other unit is in a y position but oil. Furthermore, the circuit connectionsare arranged, as will now be described,

so that when a switch is in bit position, the unit it controls'will be completely isolated from the feed lines.

The heating units are fed from the power lines LI and L2. The power line Li is connected to lower long stationary contact 3011 by a conductor l0 and the short contact inc-opposite is connected by a conductor H to one end of each of the heating elements A and l3. The other ends of the heating elements A and B are connected by the conductor I! to the long upper contact 30/1 and wire H to the short offset upper contact 300 respectively. This other end of the heating element B and the short offset upper contact Ila are connected by a conductor ii to the lower 15 short contactv 30d. Alternatively the contacts 30g and 30d may be located above and in contact with one another on the switch base, as shown in Figures 10 and 11. The same applies to Mid and 40g.

The switch 30 is interconnected with the switch 40 by means of a conductor i6 connecting the lower short contact 30b and the lower short contact 40b and also by a conductor 11 connecting the upper short contact 30/ with the upper short contact 40!. These contacts and conductors may be considered as interlocking means since they comprise the means for interconnecting switches and 40 and causing the circuits of those switches to be interlocked.

In the switch 40 the long lower contact "a is connected by a conductor 20 with the power line Ll while the short lower contact "c opposite is connected by conductor 2i to one end of each of the heating elements M and N. The other ends of the heating elements M and N are connected with the long upper contact Inn by conductor 22 and the short offset upper contact 409 by conductor 24 respectively. This other end of the heating element M and the ofiset upper contact g may be 40 connected with lower short contact "d by a conductor l9 or as hereinbeiore indicated. The upper long contact we is connected with the power line L2 by a conductor l8.

Referring to Figure l in which the switches 5 are both in the high position, it will be noted that no switch blade is in contact with the contacts 300, 40a, 30c, be which are connected with the power lines. Hence there is no current through the heating elements, and it is impossible to get 5 a high degree of heat from both heating units at the same time. This arrangement prevents drawing excess current from thepower lines which might cause blowing out of a fuse or breaking down of the insulation due to the excess current.

\ Referring to Figures 2, 3, 4 and 5, wherein the switch 30 is in of! position and the switch 40 is in high, medium, low and oil. positions it will be noted that the switch blades of switch 30 do not in any of these positions contact with the stationary contacts 30c, 30d, 30;! and 30h. Since these stationary contacts are the only ones which are connected with the heating elements A and B, these elements are completely isolated from the power lines LI and L2 whenever the switch 30 is as in oil position. This is a desirable condition since it avoids the possibility of a short circuit occurring in case a heating unit is connected accidentally with a power line or a ground. It also avoids the possibility of a person receiving an electric shock in case his hand touches a heating unit or a portion of theelectric stove or pipe which is grounded.

Referring to Figure's S, 6, '7 and 8, the switch 40 is in on position and the switch 30 is in oil the switch 40 here has been moved 90 in advance of the high position in which it is shown in Figure 1. This position in Figure 9 of the switch to is for giving medium, heat in the unit composed of the elements M and N, and it will be noted that connections are established from power line Li through wire 2d, contact 40a, short lower blade We, long lower blade 10c, short lower contact tile, wire it and heating element M, wire 22, long upper contact this, long upper blade b, short upper blade that, long upper contact me, wire It to the power line L2. In Figure 9 the switch fit] is in high position, but no circuit is completed through elements A and H since no switch blades engage with the contactstflc and the, which are directly connected to the power line, nor with 3% and till, which can he connested indirectly with the power lines. By referring to Figures 1 and 3 it will be noted that, in the high and medium positions there shown for switch til, no connections are completed from the power lines to contact tub and till, and thus it appears that only when switch til is oil can the circuit be completed by switch ill to give high heat in elements A and B. (See Figure 6.) In like manner high heat can be obtained by switch (it for heater elements M and N only when switch 80 is in off position.

It will be understood that when switch it! is in high position switch ill may he moved into niediuin (Figure 9) and low positions to give medium and low heat in elements M and lil. 'ilhe cir cult connections for low position of switch til when switch Bil is in high position may be readily traced in the drawings with the help oi the fore going description. Likewise, can the circuits be traced when switch it is in high position and is in multiple across the lines, the connections for.

connecting the elements of the other heating unit in multiple are disabled.

Many modifications within the scope of my in vention will occur to those skilled in the art. Therefore I do not limit myself to the specific form shown.

i claim:-

l. In an electric circuit, a pair of supply lines, a plurality of resistance units each comprising a plurality of resistance elements, in combination 7 with means for connecting the elements of each of said units in multiple or in series and for establishing the connections to connect the elements of one unit in series or multiple when the elements of the remainder are disconnected or are connected in any way but in multiple, and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short; blades for selectively engaging the stationary contacts.

2. In an electric circuit, a pair of supply lines,

a plurality of resistance units each comprising a plurality of resistance elements, in combination with means for. connecting the elements of each of said units in multiple or in series, or-connecting only one element of each unit directly across the lines and for establishing the connections to connect the elements of one unit in series or multiple or with one element across the lines when the elements of the remainder are disconnected or are connecied any way but in multiple, and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts.

3. In an electric circuit, a pair of supply lines, a plurality of resistance units each comprising a plurality of resistance elements, in combination with means for connecting the elements of each of said units in multiple or with one element directly across the supply lines and for establishing the connections to connect the elements of one unit in multiple or with only one element across the lines when the elements of the remainder are disconnected or are connected in any way but in multiple. and for insolating each unit completely from the supply lines when itsswitch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts,

connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts.

4. In an electric circuit, a pair of supply lines, a plurality of resistance units each comprising a plurality of resistance elements in combination with means for connecting said units to the supply lines with their respective elements in different circuit arrangements to give difierent effects in said units and for establishing the connections to complete the various possible circuit arrangements in one unit when the elements of the re mainder are disconnected or are connected in any way but in multiple, and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts.

5. In. an electric circuit, a pair of supply lines, a plurality of resistance units each comprising a plurality of resistance elements, in combination with means for connecting the elements of each of said units in series or with one element (ll-=- rectly across the supply lines and for establishing connections to connect the elements of one unit in series or with only one element across the lines when the elements of the other units 75 are disconnected or are connected in any way but in multiple and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts.

6.In an electric circuit, a pair of supply lines, two resistance units each comprising a plurality of resistance elements, in combination with means for establishing the connections to connect the elements of either one or the other of said units in series or multiple when the elements of the remaining unit are disconnected or are connected in any way but in multiple, and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality oi long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts.

'7. In an electric circuit, a pair of supply lines, two resistance units each comprising a plurality of resistance elements, in combination with means for establishing the connections to connect the elements of either one or the other of said units in series or multiple or with one element across the lines when the elements of the remaining unit are disconnected and are connected any way but in multiple, and for isolating each unit completely from the supply lines when its switch is in position to break the circult through it, said means comprising a pair oi? switches each having a plurality of long and short stationary contacts, connections intercom, necting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts.

8. In an electric circuit, a pair of supply lines, two resistance units each comprising a plurality of resistance elements, in combination with means for establishing the connections to connect the elements of either one or the other of said units in series or with one element across the line when the elements of the remaining unit are disconnected or are connected in any way but in multiple, and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts 10 in said switches with long and short blades for selectively engaging the stationary cont-acts.

9. In an electric circuit, a pair of supply lines, two resistance units each comprising a plurality of resistance elements, in combination with 15 'means for establishing the connections to connect the elements of either one or the other of said units in multiple or with one element across the line when the elements of the remaining unit are disconnected or are connected in any :0 way but in multiple, and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts. 10. In an electric circuit, a pair of supply lines, two resistance units each comprising a plurality of resistance elements, in combination with means for establishing the connections to connect the elements of either one or the other of said units in various circuit arrangements to give diflerent effects in said units when the elements of the remaining unit are disconnected or are connected in any way but in multiple and for isolating each unit completely from the supply lines when its switch is in position to break the circuit through it, said means comprising a pair of switches each having a plurality of long and short stationary contacts, connections interconnecting said switches and said elements and supply lines, and movable contacts in said switches with long and short blades for selectively engaging the stationary contacts.

SAMUEL A. GRISWOLD. 50 

